Excavation of a site in Zhangjiakou city in the Heibei province, which is near the Great Wall of China, is being blamed for causing a section of the ancient wall to collapse.

Reports indicate that a section of the wall nearly 100 feet long collapsed as working was being done around the site.

"There is an investigation into the causes of the collapse. A number of things may have contributed, including the building work," a city official told local media, adding that "conservation and a rebuilding plan is already underway."

The Great Wall of China was built in the seventh century B.C. to keep invaders out of the Chinese Empire. Over the centuries parts of the wall have had to be rebuilt and the height of the wall in some parts has been reduced from 16 feet to less than six feet.

Because of the numerous restorations over the generations, the iconic square-shaped lookout towers have disappeared completely while most western sections of the wall, which were constructed from mud rather than brick and stone, were more susceptible to erosion.

The Great Wall in not actually one single wall, rather it is many walls twisting along an east-west path across northern China. The total length of the Great Wall is about 5,000 miles, although experts point out that if all the sections of the wall were included the length is would be around 14,000 miles.

In 2003, In order to preserve the great wall, Beijing announced the first regulations governing the wall and then last December a new national law was announced by the central government to protect the wall.

The new law states that it is now illegal to deface the bricks, remove stones or bricks from the wall or build a house against the wall.

The law also states that "all citizens, legal entities and organizations" are responsible for protecting the wall and reporting any illegal activity, according to the Telegraph.